Redetachable device

ABSTRACT

A redetachable self-adhesive device 
     a) whose reverse face is bonded with a strip of a double-sidedly adhering adhesive sheet in such a way that one end of the adhesive sheet projects beyond the device as a grip tab, 
     b) the adhesive sheet is such that the bond made with it is redetachable by stretching pulling on the grip tab of the strip in the direction of the bond plane, 
     wherein 
     c) on its reverse face ( 2 ) the device ( 1 ), in the region ( 3 A,  3 B) situated opposite the grip tab ( 6 ) of the adhesive sheet strip ( 5 ), is designed in such a way that it has a distance (V) from the grip tab ( 6 ).

The invention relates to a redetachable device for a bond with anadhesive sheet, pressure-sensitively adhesive on both sides, which isredetachable without residue or destruction by extensive stretching inthe bond plane, and to its use.

Elastically or plastically highly extensible (strippable) self-adhesivetapes which can be redetached without residue or destruction by means ofextensive stretching substantially within the plane of the bond areknown from U.S. Pat. No. 4,024,312, DE 33 31 016, WO 92/11332, WO92/11333, DE 42 22 849, WO 95/06691, DE 195 31 696, DE 196 26 870, DE196 49 727, DE 196 49 728, DE 196 49 729, DE 197 08 366, DE 197 20 145,WO 99/31193, and WO 99/37729.

They are frequently employed in the form of single-sidedly ordouble-sidedly pressure-sensitive adhesive sheet strips (adhesive tapestrips, adhesive strips), which preferably have a nonadhesive grip tabregion from which the process of the attachment is initiated. Particularapplications of such self-adhesive tapes can be found, inter alia, in DE42 33 872, DE 195 11 288, U.S. Pat. Nos. 5,507,464, 5,672,402, and WO94/21157. Specific embodiments are described, for example, in DE 44 28587, DE 44 31 914, WO 97/07172, DE 196 27 400, WO 98/03601, and DE 19649 636, DE 197 20 526, DE 197 23 177, DE 297 23 198, DE 197 26 375, DE197 56 084, and DE 197 56 816.

Preferred areas of use of the abovementioned adhesive sheet stripsinclude, in particular, the residuelessly and nondestructivelyredetachable fixing of light to moderately heavy articles in the home,workplace, and office segments. In these applications they replaceconventional fastening means, such as hooks, pins, thumbtacks, nails,screws, conventional self-adhesive tapes, and liquid adhesives, to namebut a few. Key to the successful use of the abovementioned adhesivesheet strips is not only the possibility of residueless andnondestructive redetachment of bonded articles but also their quick andeasy bonding, and the secure hold they provide for the envisaged periodof bonding.

In accordance with the abovementioned patent documents,pressure-sensitive adhesive compositions suitable for such productsinclude in particular those based on natural rubber/resin mixtures,synthetic rubber/resin mixtures, and acrylate copolymers. In practicalapplication, however, it is pressure-sensitive adhesive compositionsbased on styrene block copolymer/resin mixtures that have taken over themarket. For instance, the products tesa® Power-Strips®, tesa®Power-Strips® mini, and tesa® Poster-Strips from Beiersdorf AG, Hamburg(D), Command® Adhesive from Minnesota Mining and Manufacturing Co. Inc.,St. Paul (US), and Plastofix® Formule Force 1000 from Plasto (F), allutilize a pressure-sensitive adhesive composition based on styrene blockcopolymer/resin mixtures.

Also sold commercially are devices made of plastic, normally bonded inthe form of hooks with abovementioned double-sidedlypressure-sensitively adhesive products and redetachable without residueor destruction by extensive stretching in the bond plane.

Devices of this kind are described, inter alia, in DE 42 33 872 and WO94/21157. DE 42 33 872, for instance, describes a redetachableself-adhesive hook equipped with a pull-release adhesive sheet(available commercially, inter alia, under the designation “tesa®Powerstrips® system hook”). Devices which can be used in this way arecomposed of only one plastic part or have a modular compositioncomprising two or more functional parts. The abovementioned system hookis composed of 2 functional parts, a baseplate and a mountable hookmolding.

In the course of practical use of such devices, however, problems mayoccur, especially during redetachment by extensive stretching of theadhesive sheets used. At the extensional stress which occurs in thisprocedure, the effect of debonding is of substantial significance, inaddition to a sufficiently high tensile strength. It is also necessaryto ensure that the pulling of the adhesive strips takes placepreferentially in the bond plane.

One possibility of circumventing the restriction just described can befound in EP 832 588, in which a redetachable self-adhesive device isprovided with regions of low static friction and sliding friction. For adevice to have such a construction, however, complex productiontechnologies are needed (2-component injection molding and many more).

An additional disadvantage with the solutions known to date is that thepressure-sensitive adhesive compositions used which are able to meet thetypical profile of requirements for the applications described, arerestricted to a relatively large extent in the degree of freedom of theformulations and in the selection of the base materials. In many cases,high-grade modern adhesive formulations are unsuitable for the describedredetachment mechanism by the bonding on stretching in the bond plane,since debonding is not sufficient. In this case the static friction andsliding friction, especially in edge regions of the bonded devices, aretoo high, and the adhesive strip then tends to tear, so that tracelessredetachment of the device is no longer possible.

In addition, misapplications may occur for the inexperienced user if sheor he fails to perform the stretching operation in one step and insteadcarries out stretching and release a number of times, in stages, so thatin moments of release the adhesive strip may become adhesively bondedagain, particularly to the edge regions of the device. This renewedbonding under simultaneous extensional stress then leads in many casesto the adhesive strips becoming torn off, as a result of additionalfrictional forces which occur.

Effected to a particularly great extent by these application areas areadhesive compositions which, in principle, have a tear propagation forcewhich is much less than the tear force. Under the above-describedinfluences of rebonding and reduced debonding such adhesive compositionsare subject to very small instances of damage superficially, which owingto the low tear propagation force may lead very quickly to tearing ofthe adhesive strip.

Applications of these adhesive films, redetachable by extensivestretching, for decoration purposes are accumulating to an increasingextent. In such applications, visual aspects are much more significant.In these cases, particular value is placed by the users on the fact thatthe adhesive strips and devices (e.g., hooks) used appear visually in asunobtrusive a way as possible in relation to the decoration that is tobe affixed. The prior art does not describe how a device (e.g., hooks,baseplates) is to be modified in such a way that the favoredredetachment characteristics and the described optical neutralityfunction in combination. Thus, DE 197 29 706 describes regions whichreduce static and sliding friction and which are composed of polymericmaterials. However, these regions are normally not neutrally coloredand/or not transparent in terms of their visual appearance, so thataccording to this description a desired lack of visual obtrusiveness inthe user's applications cannot be achieved.

It was an object of the present invention to remedy this situation and,in particular, to be able to offer the user a product of consistentlyhigh and uniform quality without him or her when using said productbeing disappointed in terms of the performance of a bond made using itor its subsequent parting, in particular as a result of tearing.

The object is achieved by means of a redetachable self-adhesive device:

a) whose reverse face is bonded with a strip of a double-sidedlyadhering adhesive sheet in such a way that one end of the adhesive sheetprojects beyond the device as a grip tab, b) the adhesive sheet is suchthat the bond made with it is redetachable by stretching pulling on thegrip tab of the strip in the direction of the bond plane, wherein c) onits reverse face (2) the device (1), in the region (3A, 38) situatedopposite the grip tab (6) of the adhesive sheet strip (8), is designedin such a way that it has a distance CV) from the grip tab (6).

In another embodiment, the distance (V) of the redetachableself-adhesive device is 0.1-1.5 mm, in particular 0.2-1 mm.

In another embodiment, the distance (V) ascends toward an edge (4, 4′)over which the grip tab (6) protrudes. The edge (4, 4′) beyond which thegrip tab (6) projects has a low static friction and sliding friction, inparticular a low-enemy polymer surface.

In another embodiment, the distance (V) rises continuously ordiscontinuously in the form of steps, wherein the distance (V) risescontinuously in the formation of an angle (a) of 5°-120°, in particular10°-90°, between the area of the region (3A, 38) which lies opposite thegrip tab (6) and that area of the grip tab (6) which is oppositethereto.

In another embodiment the breadth of the region exhibiting the distance(V) is equal to or greater than at least the breadth of the strip (5),and measures 1-20 mm, in particular 2-12 mm, in its depth (W).

In another embodiment, the region (3A, 38) which lies apposite the griptab (6) is additionally roughened, and in particular has an averageroughness R_(a) of 0.4-25 μm, in particular 2-20 μm. The region (3A, 38)exhibiting the average roughness R_(a) has an average depth of roughnessR_(z) of 1-150 μm, in particular 2-100 μm. The region (3A, 38)exhibiting the average roughness R_(a) is reduced together with thedevice (1) by injection molding, or is produced in a subsequentworkstep, in particular by etching, grinding, embossing or sparkerosion.

In another embodiment, the reverse face (2) of the device (1) hasalternative edges (4, 4′) by way of which the adhesive sheet strip (5)may be stuck on with its grip tab (6) projecting beyond said edges,there being provided corresponding regions (3A, 38) having in each casea distance (V).

In another embodiment, the device (1) besides the adhesive sheet strip(5), there are spacers (8A, 88, 8C) whose height is less than thethickness of the adhesive sheet strip (5).

In another embodiment, the adhesive sheet strip (5) is elastically orplastically extensible with or without a crier in between.

In another embodiment, the adhesion of the adhesive sheet strip (5) isless than the cohesion, the adhesion largely disappears when the sheetis extended, and the ratio of peel force to tear load is at least 1:2.0, the adhesive sheet being based on thermoplastic rubber andtackifying resins, with high elasticity and low plasticity.

In another embodiment, the reverse face of the adhesive sheet strip (5)is lined with a release laminate, such as a siliconized release paper ora release film.

In another embodiment, the device has fixing means such as hooks,latching projections or the like, located on its front face orlaterally.

The invention also contemplates using the device for redetachableself-adhesive fastening and redetachment by puffing on the grip tab ofthe strip in the direction of the bond plane.

It has in fact been found that the devices or plastic parts, especiallyhooks, of this kind that exist have not been paid the attentionappropriate to them, either in the patent literature or in practical useof the various commercially available products. Indeed, despite all ofthe efforts made to date, tearing occurs again and again duringdetachment. Quite evidently, the problem has not been fully recognized.It is found that the adhesive sheets present on the market to date,which are redetachable without residue or destruction by extensivestretching in the bond plane, do not possess a device rendering themcapable of very largely retaining tear-free redetachment even underrelatively disadvantageous debonding characteristics and applicationinfluences. Equally, in many cases, the desired, visually neutralappearance during application is not achieved.

Adhesive Sheets

Adhesive sheets to be protected in accordance with the invention againsttears include in particular those corresponding to U.S. Pat. No.4,024,312, DE 33 31 016, WO 92/11333, DE 42 22 849, WO 95/06691, DE 19626 870, DE 196 49 727, DE 196 49 728, DE 196 49 729, and DE 197 08 366which utilize pressure-sensitive adhesive compositions based onelastomer/resin mixtures. In particular, the adhesive sheets used inaccordance with the invention utilize pressure-sensitive adhesivecompositions based on polymeric dienes, such as natural rubber,synthetic polyisoprene, and polybutadiene, for example. Moreover, theseadhesive sheets utilize pressure-sensitive adhesive compositions basedon styrene block copolymers. Preferred styrene block copolymers includethose containing elastomer blocks based on 1,3-dienes, such aspolyisoprene, polybutadiene, isoprene-butadiene copolymers, and thepartly or fully hydrogenated analogs corresponding to the aforementionedsystems. Furthermore, these adhesive sheets utilize pressure-sensitiveadhesive compositions based on random copolymers of conjugated dienesand further polymerizable compounds, such as styrene-butadienecopolymers or acid-functionalized styrene-butadiene copolymers, to namebut a few. Additionally, adhesive sheets to be protected in accordancewith the invention against tears utilize pressure-sensitive adhesivecompositions based on polyolefinic elastomers. A further possibility foruse in accordance with the invention are adhesive sheets withpressure-sensitive adhesive compositions based on mixtures ofabovementioned elastomers and also based on blends of abovementionedelastomers with further polymers.

Plastic Part (device)

Devices of the invention generally serve to accommodate one side of theadhesive sheet, whose other side is bonded to the selected substrate. Awide variety of different adapters, including hook bodies, may be placedon such devices in the function of a baseplate, for example. However, itis also possible for the device itself to be designed as a hook or thelike, i.e., to have a hooklike mounting means on the front face, forexample. In order to generate a high bond strength, the area of thedevice—and mandatorily not the entire molding construction—to which theadhesive sheet is applied is composed in particular of a material havingan adhesion to the adhesive sheet that is sufficient for the case inhand. Here, advantageously, suitable moldings include injection moldingcompositions which are composed of PMMA, POM, PC, polyamide, andpolyester, and especially polystyrene and/or styrene copolymers, and/ormixtures of such components.

At at least one region of the reverse face, the devices of the inventionare designed in such a way that there is a distance between the adhesivesheet strip and/or its grip tab and the edge region which lies oppositethe grip tab. This effect may be achieved especially well with injectionmolding compounds on which the adhesive strips that are to be usedexhibit a desirably good adhesion. Accordingly, it becomes possible toimplement a modification of this kind, providing security against tears,without complex use of, for example, 2-component injection moldingtechnologies, as would be necessary in accordance with EP 832 588.

With the devices of the invention, the inventive modifications maderemain material-neutral in their visual appearance; in other words, inthe eye of the user, the modifications do not bring about any visuallyunwanted changes in color and/or transparency of the materials used.Accordingly, it is also possible to provide colorless transparentdevices, for example, with correspondingly described modifications,which do not appear disruptively when viewed in the application.

The redetachability of a device of the invention may be improved stillfurther by additionally providing spacers, in particular in accordancewith DE 196 37 223. This permits tear-free redetachment even under veryhigh forces acting perpendicularly to the bond plane (e.g., excessiveapplied pressing force during parting of the adhesive bond).

The devices of the invention may be produced either by correspondingtool modification directly in the injection molding operation, or in asubsequent workstep by milling or filing, for example.

The devices of the invention develop the prior art in accordance with EP832 588 further in a different, hitherto unexplored direction. EP 832588 teaches how a plate or similar devices may be equipped in such a waythat over their peel edge, by way of which an adhesive sheet strip isdebonded by stretching pulling, the peel angle ought approximately to bea right angle, in particular an angle of 45°-135° to the bond plane;cf., e.g., claim 18 therein. This stripping at a 90° angle is intendedin particular for applications where there is not sufficient space tocarry out stripping “normally”, along the wall for instance.

To improve or enable this is not the concern of the present invention.The objective here, rather, was to reduce the tendency toward tearingduring “normal” stripping. As laid out in the introduction, thistendency toward tearing continues to be a problem. And the prior artgives little incitement, for instance spacers, for solving this problem.More extensive knowledge or incitement, however, are not offered by theprior art in this respect.

Further embodiments of the invention are shown by the devices depictedby way of example in the figures, which are not intended to representany unnecessary restriction. In the drawing,

FIG. 1 shows a side elevation of a device of the invention, with anadhesive sheet strip stuck on,

FIG. 2 shows an oblique side elevation in accordance with FIG. 1,

FIG. 3 shows an oblique side elevation of another device,

FIG. 4 shows an oblique side elevation of a further device, and

FIGS. 5 and 6 show a section in enlarged form.

In detail, FIG. 1 shows a device (1). The reverse face (2) of the device(1) is used for sticking on an adhesive sheet strip (5), the regions(3A) and (3B) of this reverse face (2) which lie against the grip tab(6) of the adhesive sheet strip (5) are specially designed. Since theuser is able to stick the adhesive sheet strip (5) onto the device (1)in such a way that the grip tab (6) is able to protrude at both one endand the other end, both regions (3A) and (3B) are designed in the mannerillustrated by examples in FIGS. 5 and 6. This prevents the user bondingthe adhesive sheet strips (5) “wrongly”; i.e., in such a way that thegrip tab (6) not designed in accordance with the invention protrudes.Accordingly, the user does not need to consult use instructions or thelike as to how he or she should stick on the adhesive sheet strip (5);instead, he or she always sticks it on “correctly”. And at the same timehe or she has the further advantage that toward the end of the strippingoperation the adhesive sheet strip (5) parts more readily from the bondand so also tends less toward tears at the end of stripping. Indeed, itis particularly at the end of stripping that the tendency toward tearinggoes up, since the force with which the user presses on the article inorder to hold it is exerted on an area which is becoming smaller andsmaller as stripping progresses—a phenomenon which may also be counteredby means of spacers.

In the region of the grip tab (6), on the reverse face (2) of the device(1), there is an edge (4) below which stripping takes place. Similarly,the corresponding edge (4′) would be that below which stripping wouldtake place were the adhesive sheet strip to be stuck on “the other wayround”, i.e., in such a way that its grip tab (6) projects beyond thisedge (4′).

Films (7A, 7B) cover the grip tab (6) in such a way that said tab is notadhesive and can therefore be gripped effectively and let go of againlater.

FIG. 2 shows the device (1) without an adhesive sheet strip (5) stuckon. Here, the designed regions (3A, 3B) are shown hatched.

FIG. 3 depicts another embodiment in which the device (1) has a reverseface (2) which serves to accommodate an adhesive sheet strip (not shown)and which has regions (3A) and (3B) designed at both ends. Additionally,the device (1) has spacers (3A, 3B).

FIG. 4 shows a further preferred embodiment of a device (1) having areverse face (2) which serves to accommodate an adhesive sheet strip(not shown) and which, in accordance with FIG. 3, is equipped withspacers (8A, 8B, 8C).

Otherwise, the designed regions (3A, 3B) are as in accordance with FIG.1; only in accordance with FIG. 4 is only one such region (3A) provided,since here, owing to the simultaneous limiting function of the spacers(8A, 8B, 8C), the adhesive sheet strip (5) can be stuck only in oneversion, namely such that its grip tab (6) projects beyond the region(3A) and hence beyond the edge (4).

The spacers (8A, 8B, 8C) are designed as ridges or segments whose heightis approximately half the thickness of the adhesive sheet strip (5) tobe applied, the distance between the spacers (8A and 8B) being chosensuch that the adhesive sheet strip (5) can easily be placed widthways inbetween them.

FIGS. 5 and 6 show in more detail, in the form of a section, how theregions (3A, 3B), designed in accordance with the invention, areconfigured.

In each case, one adhesive sheet strip (5) with grip tab (6) sticks toone device (1). The region (3A), which is only indicated in principle inFIG. 1, is now drawn in more detail, namely by means of a distance (V)between grip tab (6) and edge (4) beyond which the grip tab (6)projects. The depth (W) of the distanced region is depicted, and in theform depicted extends to approximately the “inside” end of the grip tab(6).

FIG. 5 shows a stepwise configuration, FIG. 6 a continuousconfiguration, of the distance region (3A). It is also possible (thoughnot shown) for the edge (4), below which the adhesive sheet strip (5) isextended, to be of rounded-off design.

In addition to the configuration according to the invention, it is alsopossible, advantageously, for the distance region (3A, 3B) to be ofroughened design, particularly such that the average roughness R_(a) is0.4-25 μm, with further preferred figures relating to this being givenin the subclaims.

In all of the examples below, testing was carried out with single-layeradhesive sheets which are in accordance with the definition and have thefollowing formulation:

50 parts Escorez 5600 (Exxon Chemical), 35 parts Kraton G RP 6919(Kraton), 15 parts Kraton G 1657 (Kraton), 0.5 part Irganox 1010 (Ciba).

On the abovementioned formulation in a thickness of 650 μm, a tensilestrength of 8.3 MPa and an elongation at break of 750% were measured.

EXAMPLE A

Glass-clear, colorlessly transparent plates (length×breadth=50×25 mm)having a thickness of 1.25+/−0.25 mm were injection molded frompolystyrene (PS 158 K-BASF and Empera 123-BP Chemicals) for which threedifferent modifications according to the invention were introduceddirectly in the injection molding process. At 20 mm, the distance region(3A, 3B) is as wide as the plate (and at the same time as wide as theadhesive strip); its depth (W) is 2 mm. After reaching the distance (V),the modification then runs parallel to the bond place again, with anangled characteristic. Using adhesive strips redetachable withoutresidue by stretching (for formulations see above) (L×B=50×20 mm),provided at one end on both sides with a grippable, nonadhesive region(by coverage with a siliconized 23 μm PET film) (L×B=14×20 mm), theseplates were bonded to panes of window glass such that the grippableregion reaches 0.5-1.0 mm into the joint. For this purpose, the adhesivestrip (its upper face lined with release paper) was placed onto the paneof glass and pressed on by rolling (10 m/s) over it 6 times using a 2 kgpressing roller. Following removal of the release paper, theabove-described polystyrene plates were bonded by applied pressure (10s, 100 N), acting uniformly and vertically on the entire adhesivecomposition, in such a way that the entire adhesive region of theadhesive strip was covered.

Specimens prepared in this way were subjected to storage at 40° C. for72 h. After reconditioning at 23° C. for 24 h, the specimens wereassessed by extracting the adhesive strips stretchingly from the jointby hand, by pulling on the nonadhesive grip region (the maximum angle tothe bond surface during detachment was 5°-10° C., the typical detachmentspeed approximately 10 cm/s). The assessment criterion was whether theadhesive strip could be detached in the manner described without residueor tearing.

Result:

Tear Plates* Modification* frequency (%) 3 without distance regionSmooth 63 3a with 0.3 mm step, 2 mm deep Smooth 34 3b with 0.3 step, 2mm deep Roughened 14 3c beveled, V = 0.2 mm, W = 2 mm Roughened 6*Technical data relating to the distance region: ²Averaged depth ofroughness Plate ²Average roughness R_(a) R_(z) Step 3b 3.1 μm 20.0 μm0.3 mm 3c 3.1 μm 20.0 μm 0.3 mm, 45° ²set at the injection mold inaccordance with DIN 4768

Accordingly, the tear frequency is significantly reduced.

EXAMPLE B

In accordance with example A, plates were produced by injection molding,except that in this case there were—according to No. 2c—three differentangles of inclination, with the spatial arrangement remaining the sameat V=0.3 mm and W=2 mm. Bonding, conditioning, and assessment of thespecimens took place in accordance with example A.

Result:

Tear frequency Specimen ²R_(a) ²R_(z) Angle of inclination (%) 3c.1 3.120.0 90° 29 3c 3.1 20.0 45° 6 3c.2 3.1 20.0 15° 24 ²set at the injectionmold in accordance with DIN 4768

In this example as well it is clearly indicated that, with precisionadjustment of the setting of determinant angles of inclination, anoptimum is achieved.

What is claimed is:
 1. A redetachable self-adhesive device bonded on areverse side thereof to one side of a double-sided adhesive sheet, theadhesive sheet comprising a grip tab which projects beyond one end ofthe device, the adhesive sheet being capable of being released from asubstrate to which it is bonded by grasping the grip tab and pulling onthe grip tab in a direction of a plane of a bond formed between saidadhesive sheet and said substrate, and the device comprises a region, onat least one end thereof, not abutting the adhesive sheet, but beingoffset therefrom a distance V.
 2. The device as claimed in claim 1,wherein the distance V is 0.1-1.5 mm.
 3. The device as claimed in claim2, wherein the distance V is 0.2-1 mm.
 4. The device as claimed in claim1, wherein the distance V ascends toward an edge over which the grip tabextends.
 5. The device as claimed in claim 4, wherein the distance Vrises continuously or discontinuously in steps.
 6. The device as claimedin claim 4, wherein the distance V rises continuously to an angle αof5°-120° between the region and the grip tab.
 7. The device as claimed inclaim 6, wherein the angle α is 10-90%.
 8. The device as claimed inclaim 1, wherein the region has a bread which is equal to or greaterthan at-least that of the adhesive sheet.
 9. The device as claimed inclaim 1, wherein the region measures 2-12 mm in its depth W.
 10. Thedevice as claimed in claim 1, wherein the region is roughened having anaverage roughness R_(a) of 0.4-25 μm.
 11. The device as claimed in claim10, wherein the average roughness R_(a) is 2-20 turn.
 12. The device asclaimed in claim 10, wherein the region has an average depth ofroughness R_(z) of 1-150 μm.
 13. The device as claimed in claim 12,wherein the average depth of roughness R_(z) of 2-100 μm.
 14. The deviceas claimed in claim 10, wherein the region is formed together with thedevice by injection molding.
 15. The device as claimed in claim 10,wherein the region is produced in a subsequent workstep selected fromthe group consisting of etching, grinding, embossing and spark erosion.16. The device as claimed in claim 1, wherein the region comprises edgeson which the adhesive sheet is capable of adhering and the grip tabprojecting beyond the edges is separated from the region by the distanceV.
 17. The device as claimed in claim 1, further comprising spacerswhose height is less than a thickness of the adhesive sheet.
 18. Thedevice as claimed in claim 4, wherein the edge has a low static frictionand sliding friction.
 19. The device as claimed in claim 18, wherein theedge is a low-energy polymer surface.
 20. The device as claimed in claim1, wherein the adhesive sheet is elastically or plastically extensiblewith or without a carrier in between.
 21. The device as claimed in claim1, wherein the adhesive sheet exhibits an adhesion less than itscohesion, the adhesion largely disappears when the adhesive sheet isextended, and the adhesive sheet exhibits a ratio of peel force to tearload of at least 1:2.0, and the adhesive sheet being is based onthermoplastic rubber and tackifying resins, and exhibits high elasticityand low plasticity.
 22. The device as claimed in claim 1, wherein theregion is lined with a release laminate.
 23. The device as claimed inclaim 2, wherein the release laminate is a siliconized release paper ora release film.
 24. The device as claimed in claim 1, further comprisingfixing means located on its front face and/or lateral face.
 25. Thedevice as claimed in claim 24, wherein the fixing means are hooks orlatching projections.
 26. A method of adhering and releasing a device toa substrate, the method comprising the following steps: a) providing adevice according to claim 1; b) adhering the device to a substrate byadhering a free side of the adhesive sheet to said substrate; and c)releasing the device from the substrate by pulling on the grip tab onthe adhesive sheet in a direction of a plane of a bond formed betweenthe adhesive sheet and the substrate.